Microsoft VS.NET provides design-time support for form inheritance. A derived form can be added to your solution by right-clicking on your project in the Solution Explorer window and choosing "Add..." and then "Add Inherited Form…" from the context menu.

In Visual Studio, when you select an item on a form you're building, the Property Grid appears and lets you set various properties (e.g. background color, width, height, text color, etc.) from a two-column table. This tip shows how to know which item a user selects from the drop-down list.

Return the Tag value of the selected RadioButton from the input array of controls.
This is useful when you have many radio buttons, with a value associated to each one, and want to select the value of the checked option. Instead of writing something like this:
If RadioButton1.Checked Then

Return the HTML code generated by the input ASP.NET server control
Note: the function only works with server side controls that don't generate postbacks and that can be declared outside a server-side form
Example: TextBox1.Text = GetControlHtml(DataGrid1)

When the TextMode property of a TextBox control is set to Password, the value you assign to the Text property (either declaratively or programmatically) isn't actually displayed at runtime, not even in masked mode (with the * chars). This is of course done for security reasons, because even if ...

Return a reference to the control with the specified name, searched into the specified container and its sub-controls
Note: it requires the GetAllControls function
Example: get a reference to a Label named "lblTest", and set its Text property
DirectCast(FindControl("lblTest", Me), Label).

Insert an image into a RichTextBox, in the current position
This version takes in input the target RichTextBox and the path of the image to insert
Example: InsertImageIntoRtb(RichTextBox1, "C:\test.jpg")